While they still have the trappings of a legitimate business model the underlying fundamentals of what they do as a publisher are clear. Their acceptance rates are pushed ever higher in order to maximise income from ever increasing author fees for publication. They also rely on special collections to continually increase output, while avoiding the safeguard which stable editorial collectives provide against continually pushing for greater profit. These two graphics are from an excellent report about the company here:
This isn’t an accusation of malign intent to MDPI (or their editors) because there’s a fundamental problem with the incentive structure entailed by APCs and open-access problem. I do think MDPI have followed the logic of those incentives further than the publishers I would see as legitimate and I think it’s important every academic understands the pressures of the business model here. The knowledge system is already in a terrible state. Don’t support its further deterioration by publishing with what is almost, though not quite, a predatory publisher.
Mark Carrigan 